“Unlawful” matter

§ 4006. “Unlawful” matter Upon evidence satisfactory to the Postmaster General that a person is obtaining or attempting to obtain remittances of money or property of any kind through the mail for an obscene, lewd, lascivious, indecent, filthy, or vile article, matter, thing, device, or substance, or is depositing or causing to be deposited in the United States mail information as to where, how, or from whom the same may be obtained, the Postmaster General may— (1) direct postmasters at the office at which registered letters or other letters or mail arrive, addressed to such a person or to his representative, to return the registered letters or other letters or mail to the sender marked “Unlawful”; and (2) forbid the payment by a postmaster to such a person or his representative of any money order or postal note drawn to the order of either and provide for the return to the remitters of the sums named in the money orders or postal notes.